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G4 HUNTER ON THE TEETH.
Tooth to its neck ; and these coincide with the flat, or broad
side of the fang ; so that when we look on the fore part, or on
the back part of an Incisor, we observe it grows constantly

the Colugos (Galeopithecus), which in their general organisation approach
the Lemurs, although placed by Cuvier at the end of the Bats, we find
two incisors in the upper jaw on each side, of which the two anterior
are separated by a wide interval ; in the Philippine Colugos they are
small with bilobed crowns. In Galeopithecus Temminckii the crown is an
expanded plate with three or four tubercles ; the second upper incisor
in both species is implanted by two fangs. The lower incisors are three
in number on each side. The crowns of the first two present the
form of a comb,—a configuration which, unique in Mammalia, depends
upon the prolongation of notches deeper and more numerous, but yet
analogous to the indentations on the cutting edge of the newly-formed
human incisor.
In the extensive order of Rodents, we find the incisors represented by
a large curved ever-growing pair of teeth in each jaw, which are
separated by a wide interval from the short molar series. To this there
is but one exception—the family of the Leporidce, Hares, Rabbits, and
Picas, in which a minute second incisor occurs on each side behind the
large upper scalpriform tooth. The upper incisors describe a larger
segment of a smaller circle ; the lower, a smaller segment of a larger
circle : the lower are the larger teeth, and their sockets extend to the
back part of the jaw on the inner side of the molars. These teeth are
of unlimited growth ; and if by accident the opposing teeth are lost,
they continue to grow until they describe a complete circle, perforating
the skin, and causing absorption of the bone with which they come in
contact. Throughout life the base of the tooth continues widely open,
and contains a long conical persistent pulp, which is surrounded by a pro-
gressively ossifying capsule. Near the crown an enamel-pulp is attached to
the inner side of that part of the capsule which covers the convex surface
of the curved incisor. The tooth consists of a body of dentine with a
plate of enamel on its anterior surface, and a general investment of
cement, which is, however, very thin upon the enamel. The mutual
action of the lower and upper incisors produces an oblicpiely worn
surface on the extremity of the crown, which slopes backwards from the
anterior edge of hard enamel : the resemblance so produced to the
cutting edge of a chisel has given the name of " dentes scalprarii" to
these teeth. The varieties the scalpriform incisors present in the
different species of Rodents are limited to their size, and the colour and
sculpturing of their anterior surface. In the Coypu, Beaver, Agouti,
ami siinie other species, the enamelled surface isof an orange or brownish-
red colour. In some genera the same surface presents a longitudinal
groove.